\(Cu+X_2\underrightarrow{^{to}}CuX_2\)
___\(\frac{20,25}{64+2X}\) __\(\frac{20,25}{64+2X}\)__
\(Zn+X_2\underrightarrow{^{to}}ZnX_2\)
____\(\frac{20,4}{65+2X}\)___\(\frac{20,4}{65+2X}\)__
Lượng X2 không đổi \(\Rightarrow\frac{20,25}{64X+2X}=\frac{20,4}{65+2X}\)
\(\Rightarrow X=35,5\left(Cl\right)\)
\(\Rightarrow n_{Cu}=n_{X2}=0,15\left(mol\right)\)
\(\Rightarrow a=9,6\left(g\right)\)